Methods of analyzing a sample liquid include for example methods in which a reaction liquid from the reaction of a sample liquid with a reagent is analyzed by optical means. When a sample liquid is analyzed by such means, an analyzing tool is used which provides a place for reaction. Some analyzing tools are equipped with a plurality of channels so that multiple analyses can be performed using one type of sample liquid, or so that multiple types of sample liquid can be subjected to the same analysis.
Analyzing tools equipped with a plurality of channels include those having a rectangular configuration as shown in FIGS. 13A and 13B, in which the main parts of multiple channels 90A and 90B are arranged parallel to one another. On the other hand, there are analyzing tools having multiple channels arranged radially (for example, see JP-A 10-2875 and JP-A 10-501340).
The analyzing tool disclosed in JP-A 10-2875 has a structure wherein a sample liquid is introduced from the outer edge of the analyzing apparatus via capillaries, and an enzyme reaction occurs inside the capillaries.
On the other hand, the analyzing tool disclosed in JP-A 10-501340 has a structure wherein a sample liquid is supplied to multiple channels by means of centrifugal force which is applied to the sample liquid by rotating the analyzing tool.
However, in the analyzing tool 9A shown in FIG. 13A, the operation of supplying the sample liquid is complicated by the fact that the sample liquid needs to be supplied individually to each channel 90A via liquid inlet 91A.
On the other hand, in the analyzing tool 9B shown in FIG. 13B sample liquid can be supplied to multiple channels 90B in one operation because multiple channels 90B are all connected to one liquid inlet 91B. However, as the number of channels 90B increases it becomes difficult to keep the length of channels 90B uniform. Differences in the lengths of channels 90B translate into discrepancies in the length of time it takes for sample liquid to arrive at reaction sites 92B from liquid inlet 91B. As a result, the timing of supply of sample liquid to reaction site 92B is different for each channel 90B, and the amount of time available for the reaction at each reaction site 92B is not uniform. Because this lack of uniformity is reflected in the measurement results, differences in the length of channels 90B ultimately affect measurement accuracy.
Moreover, in order to analyze by optical means sample liquid supplied to channels 90A and 90B, the analyzing tool 9A shown in FIG. 13A and the analyzing tool 9B shown in FIG. 13B require either one photometric system which is scanned or a number of photometric systems corresponding to the number of channels 90A or 90B. This in turn means a more complex photometric system, a larger analyzing apparatus, higher manufacturing costs and higher running costs.
In the analyzing tool described in Japanese Patent Application Laid-open No. H10-2875, because sample liquid need to be supplied individually to each capillary as in the analyzing apparatus 9A shown in FIG. 13A, the operation of supplying the sample liquid is complicated by the necessity for supplying sample liquid as many times as there are capillaries.
By contrast, although in the analyzing tool described in JP-A 10-501340 there is no need to supply sample liquids as many times as there are channels, the analyzing tool must be rotated at high speeds to supply the sample liquid to the channels, generating a rotational force which is directed at the sample liquid. This complicates the device for analyzing sample liquids using the analyzing tool, leading to higher manufacturing costs and also to higher running costs because the analyzing tool needs to be rotated at high speeds.